Looking forward to your updates as to what your dealer said about this.

Here's a video of my 2016 Rx FSport doing this:

https://filebin.net/md4xmz7u5bclupbz

The reving and vibration is most noticeable at the 5-10 second mark of the video.

 

Thanks for this. Yeah it does look exactly the same and this is on a warm engine as well. I am not interested in seeing how it is for the others on the forum. Does your's do it all the time or only sometimes? I am thinking this could be related to the engine self cleaning function.

 

Doesn't do this severe reving (300 rpm fluctuations) all the time, but I do see the 100-150 rpm fluctuations pretty much all the time when idling in Drive mode (on a semi-warm or warm engine).

 

In my case the rpm is fairly constant in "D" but every once in a while it surges 150 rpm or so. Spoke to the service today. They have apparently reset the ECU and cleaned the throttle body and as per them it is resolved now. I am not confident. I will collect my car tomorrow and update the findings here.

 

Slight up/down, not 150rpm jump.

 

Got the car back from Lexus service. They cleaned the throttle body (or something, I am not very technical). The surge is not happening as of now but I am pretty sure it will be back because they havent been able to diagnose why this is happening.

Thanks. Do you have an F-Sport as well? The idle surge does not happen everytime, but only sometimes and you need to keep an eye on the tacho everytime you are stopped.

 

Rock solid here -- looks like about 675 or 700 rpm, you need a magnifying glass to detect any variation.

 

It should be 700 rpm. I hooked a bluetooth OBD adapter to check the rpm's and mine keeps oscillating between 691 to 703 rpm.

 

Mine could be wriggling that much, or maybe a bit less. Considering the loads of alternator, HVAC, and water pump, which can vary, it's not surprising that it has to adjust.

 

Yes I do have f spot.

 

my 2016 F sport RPM fluctuates significantly when engine is cold. Enough to creep the car forward at traffic lights until engine warms up. Dealer told me its normal since other RXs have the same issue. They bale it on AC running in back ground at -10 degrees Celsius.....

 

Same thing happens on my 2016 RX FSport. I had always thought it was abnormal, but maybe it’s not...

 

How much does it actually fluctuate when it's cold? When it warms up, does it then idle evenly?

 

Mine does this too and I am in Melbourne where the temperature rarely goes below 4 degrees in winters!

 

Thinking of this forum thread, this morning while running an errand with my wife, I stopped at a gas station where she likes to buy a diet Coke. I let her out, then with the brake applied and while I watched the tach, I shifted out of D into neutral. The needle popped up, maybe 75 rpm, and immediately back down to ~700. I watched it while she was in the store and it was steady. After she was back in the car, I put it back in D, and the needle sagged 100 or 150 rpm very briefly, and then popped back up to ~700 where it stayed steady until I applied the accelerator. So clearly there is a feedback loop in which the computer is tightly controlling the idle rpm.